1. Field of the Invention
The present invention relates to a cosmetic container for receiving a stick-like cosmetic such as a lipstick, which can smoothly extract and retract a stick-like cosmetic such as a lipstick accommodated therein
2. Description of the Prior Art
As a main body of a conventional cosmetic container, a cylindrical body formed by pressing a flat plate, namely a so-called pressing pipe, has been used. However, a great number of steps are required for manufacturing the pressing pipe, and it is difficult to make the cylindrical body to have a cross-section of a complete circle. Therefore, in order to reduce the number of the manufacturing steps, to improve dimensional precision of the main body, and to smoothen extraction and retraction of the cosmetic relative to the container, currently a straight pipe formed by drawing is used as the main body.
FIG. 10 shows an example of a prior art cosmetic container using a straight pipe as a main body.
As shown in FIG. 10, within a casing 100 having an upper open end, a main body 101 composed of a straight pipe formed by drawing is arranged co-axially with the casing 100 and relatively rotatably therewith. There is a space between the casing 100 and the main body 101. A cylindrical outer body 105 provided with a continuous spiral groove 107 on an inner peripheral surface thereof is arranged between the casing 100 and the main body 101. The outer body 105 is integrally fitted to the bore of the casing 100. An insert sleeve 103 is integrally fixed to the upper end portion of the outer body 105 to rotatably surround the main body 101. Within the main body 101, a cosmetic holder 109 for receiving and holding a cosmetic is received. Diametrical projections 111, 111 opposed to each other are provided at the lower end portion of the cosmetic holder 109. These projections 111, 111 pass through elongated slots 113, 113 provided in the lower portion of the main body 101 to engage with the spiral groove 107. On the outer periphery of the center portion of the main body 101 is formed a projecting bead 106 which is engaged with an internal recess of the outer body 105 to prevent removal or separation of the main body 101. Reference numeral 116 indicates a cap for detachably closing the upper open end of the container.
In use, by rotating an integral assembly comprising the casing 100, the outer body 105 and the insert sleeve 103, the projections 111, 111 in engagement with the spiral groove 107 are guided along the slots 113, 113 of the main body 101 to move up and down, to achieve extraction and retraction of the cosmetic holder 109.
In such a conventional cosmetic container, the outer body 105 is in contact with the main body 101, and the insert sleeve 103 is in contact with the outer body 105 and the main body 101, respectively.
However, a straight pipe manufactured by a drawing should inevitably have a certain degree of diametrical dimensional errors. The extraction and retraction property of the cosmetic container is greatly governed by frictional resistance between the main body 101 and the outer body 105 especially at the abutment portion between the bead 106 and the recess, which, in turn, varies depending upon dimensional relationship between the main body 101, the outer body 105 and the insert sleeve 103.
For example, when a diameter of the insert sleeve 103 is relatively small to exert an excessive degree of the frictional resistance between the main body 101 and the outer body 105, the cosmetic holder 109 can not be smoothly moved.
When a diameter of the insert sleeve 103 is relatively large, the frictional resistance between the main body 101 and the outer body 105 in the abutment portion is decreased. In this case, the cosmetic holder 109 can be moved too easily, and a user would have an uncomfortable feeling in cosmetic retracting and extracting operation. Further, airtightness of the container is degraded, and there is a possibility of deteriorating the cosmetic by an invasion of the open air.
In another prior art, a lubricant such as silicon grease is applied into the contacts between the respective constituents of the container in order to smoothen extraction and retraction of the cosmetic. However, use of silicon grease is not desirable, because the cosmetic would deteriorate under the influence of components of the silicon grease during a long-term use.
It is lately in fashion to use a cosmetic hard to melt away, a moist cosmetic, etc. However, cosmetic of such a type has a relatively large content of a volatile substance. Therefore, unless the container provides a good airtightness, the cosmetic would be deteriorated. Further, when the airtightness of the container is not excellent, after the cosmetic is accommodated, so-called "slip-out" (a phenomenon that the cosmetic is contracted and consequently slipped out of the cosmetic holder); "desertion" (a phenomenon that the cosmetic cannot effectively cope with movement of the cosmetic holder) and "breakage" (a phenomenon that the cosmetic is contracted and consequently becomes easy to break). In order to prevent such phenomena, airtightness of the container becomes a critical requirement.